BIOLOGY, EXPERIMENTAL — DAVENPORT. 97 



they might thus be brought to flower and fruit in the first season, 

 but only in the evening primroses was this hope fulfilled. Owing 

 to an unfortunate delay of two months on the part of the Bauseh 

 and Ivomb Optical Company in filling our order for a soil-sterilizer, 

 recourse was had to means other than sterilization to avoid the 

 contamination of the cultures with seeds of unknown origin. For this 

 purpose sand was taken from a sand bank after the careful removal 

 of the portion which might have received seeds carried by wind, 

 birds, etc. , or which might have been brought down from above in 

 landslides. Many of the species chosen for these studies were wood- 

 land plants which find the best conditions for their development in 

 a soil rich in humus. The attempt to start them in sand resulted 

 in a greatly lessened measure of success in the germinations than 

 might reasonably have been expected if they had been sown in soil. 

 Of 128 lots of seeds sown, only 69 lots gave germinations, and in 

 many cases only one or several specimens of a species were secured. 

 Species having very small seeds, such as Hypericum and Mimulus, 

 reached the limit of their development before they were large enough 

 to be successfully transplanted from the sand to boxes of soil. 



The number of pedigree-cultures which finally found their way 

 into the garden was 48, belonging to the following 28 species : 



Aquilegia canadensis Oe. lata L. spicata 



Barbarea sp. Oe. nanella Ambrosia artemisiaefolia 



Bursa bursa-pastoris Oe. rubrinervis Chrysopsis falcata 



Sibbaldiopsis tridentata Kneiffia pumila Solidago alpestris 



Potentilla monspeliensis Lappula americana S. macrophylla 



Viola arvensis Verbascum blattaria Erigeron ramosus 



Chauiaenerion angusti- Plantago lanceolata Rudbeckia hirta 



folium P. major Helianthus annuus 



Oenothera gigas Sonchus asper H. debilis 



Oe. lamarckiana Lactuca canadensis 



In addition to these, the following species have been under observa- 

 tion, but were kept indoors, owing to their late germination : 



Draba incana arabisans Mimulus ringens Viola spp. 



Trifolium pratense Chelone glabra Sonchus oberaceus 



T. hybridum Pentstemon pentstemon 



The chief ends aimed at in the inception of these pedigree- cultures 

 were : First, to determine in each case the presence and character- 

 ization of any elementary species within the systematic species ; sec- 

 ond, to observe the nature and degree of the fluctuations normally 

 present, in order to give a basis for selecting those variations which 

 may be expected to prove transgressive or mutational ; third, to learn 

 7 



